Ageb, years, mean (SD)
|
44.7 (11.3)
|
48.1 (10.3)
|
< 0.001
|
Race, white, %
|
88.7
|
83.3
|
0.02
|
Education, ≥ 4 years of college, %
|
77.6
|
77.4
|
0.72
|
Postmenopausal, %
|
27.4
|
51.6
|
< 0.001
|
Age at menopausec, years, mean (SD)
|
49.6 (4.9)
|
48.8 (3.4)
|
0.86
|
Bilateral oophorectomy at age < 45 yearsd, %
|
49.0
|
34.3
|
0.02
|
BMI, kg/m2, mean (SD)
|
26.2 (5.1)
|
25.9 (3.1)
|
0.29
|
Physical activity, MET-h/wke, mean (SD)
|
29.4 (27.9)
|
26.0 (15.5)
|
0.29
|
Alcohol intake, g/d, mean (SD)
|
5.7 (7.5)
|
5.7 (4.8)
|
0.99
|
Smoking status, %
|
Never
|
58.8
|
52.5
|
0.55
|
Former
|
36.7
|
44.8
|
Current
|
4.2
|
2.7
|
Missing
|
0.3
|
0.0
| |
HRT ever use, %
|
15.1
|
14.5
|
0.04
|
Ever mammogramf, %
|
99.5
|
97.8
|
0.63
|
Ever pap smear, %
|
98.6
|
99.1
|
0.15
|
Current vitamin D supplement use, %
|
7.8
|
20.8
|
< 0.001
|
Current calcium supplement use, %
|
25.5
|
28.1
|
0.97
|
Bone density examination, %
|
28.9
|
43.0
|
0.02
|
Bone density examination in women aged ≥ 45 years, %
|
51.2
|
60.0
|
0.08
|
Ever broken bone, %
|
6.4
|
6.8
|
0.84
|
Family history of breast cancer, %
|
No family history
|
14.7
|
38.9
|
< 0.001
|
First-degree relative only
|
64.8
|
50.7
|
First- and second-degree relatives
|
17.0
|
9.0
|
Missing
|
3.5
|
1.4
|
BRCA1/2 statusg, %
|
Negative
|
69.7
|
73.9
|
0.33
|
Positive
|
27.3
|
19.4
|
Variants of uncertain significance
|
2.9
|
6.7
|
Age at diagnosis, years, mean (SD)
|
–
|
46.8 (10.2)
|
–
|
Time from diagnosis to baseline, years, mean (SD)
|
–
|
1.4 (1.3)
|
–
|
Invasive breast cancer (stage I–III), %
|
–
|
82.5
|
–
|
Estrogen receptor statush, %
|
–
| |
–
|
Positive
|
–
|
75.9
|
–
|
Negative
|
–
|
23.6
|
–
|
Missing/untested
|
–
|
< 1.0
|
–
|
HER2 statush, %
|
–
| |
–
|
Positive
|
–
|
14.4
|
–
|
Negative
|
–
|
81.6
|
–
|
Missing/untested
|
–
|
3.5
|
–
|
Triple-negative statush, %
|
–
|
19.0
|
–
|
Breast cancer treatmenti,j, %
|
–
| |
–
|
Surgery
|
–
|
100.0
|
–
|
Chemotherapy
|
–
|
49.8
|
–
|
Hormone therapy, any
|
–
|
65.4
|
–
|
Hormone therapy, by typek
|
–
| |
–
|
Tamoxifen
|
–
|
67.4
|
–
|
Aromatase inhibitor
|
–
|
41.3
|
–
|